Quick recap
Two years later, the Autobots and the military have formed NEST to hunt the last Decepticons. Soundwave steals the last known AllSpark shard, and the Constructicons use it to revive Megatron. Sam, now in college, touches a smaller shard and starts seeing Cybertronian symbols in his head. Megatron returns to serve the Fallen, one of the ancient Primes. Protecting Sam, Optimus fights Megatron and Starscream and dies. With Mikaela, Leo and Simmons, Sam wakes the old Seeker Jetfire, who teleports them to Egypt to find the Matrix of Leadership. At Giza, Megatron kills Sam, but the Primes bring him back and hand him the Matrix, which revives Optimus. Armed with Jetfire's parts, Optimus destroys the Fallen's Star Harvester, kills him and wounds Megatron, who flees with Starscream. Sam goes back to college.

